Spray gun



June 26, 1934. McINTQSH 1,964,127

SPRAY GUN Filed Jan. 7. 193]. 2 Sheets-Sheet l INVENTOR.

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' ATTORNE June 26, 1934. R. D. M INTOSH 1,954,127

SPRAY GUN Filed Jan. '7, 1931 2 Sheets-Sheet 2 a v N H 1/4 1 4 l kw m .Patented June 26, 1934 FFICE SPRAY GUN Robert D. McIntosh, River Forest, 111., assignor to The imperial Brass Manufacturing Company, Chicago, Kit, a corporation of Illinois Application January 7, 1931, Serial No. 507,120

13 Claims.

My invention is concerned with spray guns in which a blast of air is employed to spread paint or some such liquid from a reservoir over the siuface to be painted or decorated, and is designed to produce a device of the class described which shall be simple in structure, eiTective in operation, and more especially one in which the mechanism can be readily disassembled for cleaning, and then as readily reassembled.

.10 To this end, it consists of a novel combination of elements, all as will be hereinafter fully described, and particularly pointed out in the claims.

To illustrate my invention, I annex hereto two sheets of drawings, in which the same reference characters are used to designate identical parts in all the figures, or" which,

Fig. 1 is a side elevation of the complete spray gun, with a portion of the handle in central section;

Fig. 2 is a central vertical section of most of the gun, but on an enlarged scale, and with both valves closed;

Fig. 3 is a similar view, but with both valves opened, as they are when in use; and

Figs. 4, 5, 6 and 7 are sections on the lines 44, 55, 66, and 7-7, respectively of Fig. 2.

In carrying out my invention in its preferred form, I employ a casting made up of the handle 10, and the rear body portion 11 and the front body portion 12 connected by the yoke 13 and the bar 14. The handle has therein the passage 16 adapted to. be connected by the coupling 1'? with a supply of compressed air, and opening at its upper end into the passage 18 drilled through to the rear body portion and connected therein to the passage 19, in turn drilled through the portions 12 and 14 to connect therewith. The lower end of the passage 18 is closed by a plug, and the passage of air therethrough is controlled by the air valve 20 having the stem 21 extending through the aperture 22 bored in the handle and provided with the packing 23 and nut 24 screwed therein to prevent leakage. The valve seat 25 is formed on the inner end of the tube 26 screwed into the larger passage 2'1 coaxial with the aperture 22 and having the helically-coiled expanding spring 28 therein to hold the valve 28 seated. The tube 27 has the enlargement 29 on its outer end. to which a wrench may be applied, and the threaded plug 30 to close it and co-operate with the spring 28, together with the apertures 31 therein near its inner end to permit the passage of air to the valve 20, so that as the trigger 32, fulcrumed on the yoke 13 by the screws 33, is swung to the position shown in Fig. 3, the valve 20 will be opened to allow the compressed air to pass through and out of the passage 19. It will be obvious that the structure so; far described can be readily assembled and disassembled if the valve 20 needs attention.

The forked portion 34 of the trigger 32 embraces the portion 14 and has the pair of screws 35 passed through apertures therein and threaded into the collar 36 (see Fig. 4) mounted to slide on the tube 37 fitted at its rear end into the large cylindrical bore 38 formed in the rear portion 11 of the casting and having near its forward end the tapered offset 39 co-operating with the correspondingly tapered seat 40 formed. on the rear end of the bore 41 extending through the front portion 12. When the trigger 32 is pulled back far enough this collar 36 engages the ends of the bar 42 extending through and adapted to be moved back and forth in the pair of opposed elongated slots 43 formed in the tube 37, and this bar 42 has an aperture 44 in the center thereof, through which passes the needle-valve rod 45, and which has its rear end screwed into the central portion of the sleeve 46, the large inner portion of which slides in the tube 3'7, while its reduced outer portion slides through an aperture in the plug 47 screwed into the outer end of the tube 37. The helicallycoiled expanding spring 48 surrounds the reduced portion of the tube 37 between the inner end of the plug 47 and the shoulder formed by said reduced portion, said spring 48 acting to keep the needle valve 45 held yieldingly in its closed position when the trigger 32 is in the inoperative position shown in Fig. 2. S A very weak helically-coiled expanding spring surrounds the needle-valve rod 45 between the inner end of the slots 43 and the bar 42, and serves to keep the bar pressed against the end of the sleeve 46. It will be obvious that by turning the enlarged end 49 of the sleeve 46, the distance that the sleeve 46 may be drawn back before the trigger 32 strikes the stop 50 on the handle can be adjusted, and in this way the maximum amount that the valve 45 can be opened in any particular adjustment is regulated. When the knob 49 is turned clockwise, the valve rod 45 is drawn by the action of the screw threads into the sleeve 46, since the friction of the packing, etc., to be hereinafter described prevents it from turning with the sleeve, and vice versa, when it is turned anti-clockwise. As seen in Fig. 2, the collar 36 always stands a little distance away from the bar 42, so that the air is turned on by the opening of the valve 20 before the needle 0 valve is opened, and the extent to which it can be opened is governed by the amount of lost motion between the collar 36 and the bar 42, since the sleeve 46 cannot be moved by the trigger 32 until the collar 36 contacts with the bar 42, and then there is only so much more possible movement before the yoke of the trigger 32 strikes the under side of the part 11 and prevents any further movement of the needle valve 45. It will be seen that the amount of lost motion will be regulated by the extent that the needle-valve rod 45 is screwed into the sleeve 46.

The inner end of the tube 37 is reduced and screwed into the end of the needle-valve seat tube 51, which extends into the bore 41 and has the tapered shoulder 52 co-operating with the outer end of the bore 41 to form an air and liquid tight joint, as it is drawn into place by the turning of the tube 37 when the parts are assembled. A connection 53 for the paint supply is screwed into the boss 54 formed on the under side of the part 12, and its reduced upper end may be beveled to co-operate with the beveled annular seat 55 forming the bottom of the port 56 extending through the adjacent part of the portion 12 to the cylindrical paint chamber 57 in the tube 51, with which it is connected through the openings 58 formed therein. The reduced upper end of the connection 53 leaves an annular space 59 around it, through which the air in the passage 19 passes during the operation of the device. The rear end of the paint chamber 57 is made air and liquid tight by reason of the packing nut 60 screwed into the bore 61 formed in the inner end of the tube member 37 and co-operating with the packing 2 therein, which is kept air-tight against the needle-valve rod 45 by the helically-coiled expanding spring 63 in the bore co-operating with the washer 64 placed in the bore to receive the pressure of the spring.

The needle-valve seat tube 51 has its outer end enlarged to form the generally conical head 65 which has the two angles, as shown, and with which co-operates the head 66 which is held in place by the threaded collar 67 screwed on to the correspondingly threaded end of the part 12, and having on its outer end the internal shoulder 68 co-operating with the external shoulder 69 formed on the inner end of the head 66. The head 65 has at its rear end the annular flange '70 interrupted by the two opposed recesses 71 which form the ends of the shallow channels '72 formed in the face of the head 65, and the head 66 is of the internal shape to co-operate with the head 65 and form passages for the air through the channels '72 to the ends of said channels, where they open into the conical space 73 which terminates in the aperture '74 in the head 66, through which the air passes outward in a hollow blast around the cylindrical tip 75 of the conical head 65. The small port 76 in the head 65, which is normally closed by the tapered end of "i6 needle valve, permits the paint to pass out as it is drawn through said port by the suction of the compressed air passing outwardly around it or by the pressure on the liquid s pply. The end of the body portion 12 has the pin 7'7 therein co-operating with one of the recesses 71 to insure the member 51 being properly seated so that one of the openings 58 will register with the port 56.

If the head 56 is to be provided with the converging ports '18 to flatten the spray, I provide therefor lugs 79 of the proper shape so that the ports 78 will converge in the right position for said flattening action, and these ports 78 are connected with the air supply by passages 80 drilled therein and extending to the rear of the head 66. In order to obviate the necessity of drilling these passages 80 of different diameters for different degrees of the flattening action, as has been the practice heretofore, and which is especially difficult where the passages are small, I form all the heads 66 with these passages 86 of uniform diameter of the largest size necessary, and when finer passages are needed, I form them by inserting plugs 81 in the inner ends of said passages, and these plugs have holes 82 drilled therethrough of the desired size to furnish the desired amount of the flattening action.

The operation of my improved spray gun will be readily apparent, and especial attention is called to the fact that the parts can be so readily assembled and disassembled when cleaning is needed. All that is necessary to get at the mech anism in the body is to screw off the collar 67, when the head 66 is removed, after which the tube 37 is turned by a wrench applied to the enlargement 83 on its rear end, when it will be screwed out of the member 51, and when it is thus screwed out, said member 51 is free to be with-- drawn from its bore.

While I have shown and described my invention as embodied in the form which I at present consider best adapted to carry out its purposes, it will be understood that it is capable of modifications, and I do not desire to be limited in the interpretation of the following claims except as may be necessitated by the state of the prior art.

What I claim as new, and desire to secure by Letters Patent of the United States, is:

1. In a spray gun, the combination with a body portion having a large bore extending therethrough divided into two parts by a gap in said body, of a tube adapted to extend through the rear portion of the bore and seated in the rear end of the front portion thereof, a liquid-nozzle tube extending from the front end of the front portion of the bore toward the rear end thereof to be screw-threaded onto the forward end of the first-mentioned tube, and a needle valve for said liquid-nozzle tube.

2. In a spray gun, the combination with a body portion having a large bore extending therethrough divided into two parts by a gap in said body, of a tube adapted to extend through the rear portion of the bore and seated in the rear end of the front portion thereof, a liquid-nozzle tube extending from the front end of the front portion of the bore toward the rear end thereof to be screw-threaded onto the forward end of the first-mentioned tube, and a needle valve for said liquid-nozzle tube extending into the first tube through a spring-pressed packing placed in the forward end thereof.

3. In a spray gun, the combination with a body portion having a large bore extending therethrough divided into two parts by a gap in said body, of a tube adapted to extend through the rear portion of the bore and seated in the rear end of the front portion thereof, a liquid-nozzle tube extending from the front end of the front portion of the bore toward the rear end thereof to be screw-threaded onto the forward end of the first-mentioned tube, a needle valve for said liquid-nozzle tube, and an adjusting tube to regulate the extent to which the needle valve may be displaced threaded on to said needle valve.

4. In a spray gun, the combination with a body portion having a large bore extending therethrough divided into two parts by a gap in said body, of a tube adapted to extend through the rear portion of the bore and seated in the rear end of the front portion thereof, a liquid-nozzle tube extending from the front end of the front portion of the bore toward the rear end thereof to be screw-threaded onto the forward end of the first-mentioned tube, a needle valve for said liquid-nozzle tube, an adjusting tube to regulate the extent to which the needle valve may be displaced threaded on to said needle valve, and a spring co-operating with the adjusting tube to hold the valve closed.

5. In a spray gun, the combination with an elongated barrel terminating in a spray nozzle, of a needle valve co-operating with the nozzle extending through the barrel, an abutment carried by said needle valve, a trigger, a collar on said barrel connected to the trigger and moved thereby, and means for adjusting the position of the abutment relative to the collar to regulate the amount of lost motion between them.

6. In a spray gun, the combination with an elongated barrel terminating in a spray nozzle, of a needle valve co-operating with the nozzle extending through the barrel, an abutment carried by said needle valve and held from rotation thereon, a trigger, a collar on said barrel connected to the trigger and moved thereby, and an adjusting sleeve threaded on to the adjacent end of the needle valve to move the abutment relative to the collar.

'7. In a spray gun, the combination with an elongated barrel terminating in a spray nozzle, of a needle valve co-operating with the nozzle extending through the barrel, an abutment carried by said needle valve and held from rotation thereon, a trigger, a collar on said barrel connected to the trigger and moved thereby, an adjusting sleeve threaded on to the adjacent end of the needle valve to move the abutment relative to the collar, and a spring co-operating with the adjusting sleeve to hold the needle valve closed.

8. In a spray gun, the combination with a body portion having a large bore extending therethrough but divided into two parts by a gap in said body, of a tube adapted to extend through the rear portion of the bore and seated in the rear end of the front portion thereof, a liquid-nozzle tube extending from the front end of the front portion of the bore toward the rear end thereof to be threaded onto the forward end of the firstmentioned tube, a needle valve for said liquidnozzle tube extending through both of said tubes, an abutment carried by said needle valve, a trigger, a collar on said first-mentioned tube connected to the trigger and moved thereby, and means for adjusting the position of the abutment relative to the collar to regulate the amount of lost motion between them.

9. In a spray gun, the combination with a body portion having a large bore extending therethrough but divided into two parts by a gap in said body, of a tube adapted to extend through the rear portion of the bore and seated in the rear end of the front portion thereof, a liquidnozzle tube extending from the front end of the front portion of the bore toward the rear end thereof to be threaded onto the forward end of the first-mentioned tube, a needle valve for said liquid-nozzle tube extending through both of said tubes, an abutment carried by said needle valve,

a trigger, a collar on said first-mentioned tube connected to the trigger and moved thereby, and an adjusting sleeve threaded on the adjacent end of the needle valve to move the abutment relative to the collar.

10. In a spray gun, the combination with a body portion having a large bore extending therethrough but divided into two parts by a gap in said body portion, of a tube adapted to extend through the rear portion of the bore and seated in the rear end of the front portion of the bore, an air-nozzle tube extending from the front end of the front portion of the bore toward the rear end thereof to be screw-threaded on to the forward end of the first-mentioned tube, a needle valve for said nozzle tube extending into the firstmentioned tube, opposed elongated slots in said first-mentioned tube, an abutment splined on said needle valve and extending through said slots, a trigger, a collar on the first-mentioned tube connected to the trigger and moved thereby, and means for adjusting the position of the abutment relative to the collar to regulate the amount of lost motion between them.

11. In a spray gun, the combination with a body portion having a large bore extending therethrough, of a tube adapted to extend through the rear portion of the bore and seated against a shoulder formed by a reduction in the diameter of the bore, a liquid-nozzle tube extending from the front end of the bore toward the rear thereof to be screw-threaded onto the forward end of the first-mentioned tube, said tubes being both adapted to be freely withdrawn from the body portion when they are unscrewed from each other and a needle-valve for said liquid-nozzle tube.

12. In a spray gun, the combination with a body portion having a large bore extending therethrough, of a tube adapted to extend through the rear portion of the bore and seated against a shoulder formed by a reduction in the diameter of the bore, a liquid-nozzle tube extending from the front end of the bore toward the rear thereof to be screw-threaded onto the forward end of the first-mentioned tube, said tubes being both adapted to be freely withdrawn from the body portion when they are unscrewed from each other and a needle valve for said liquid-nozzle tube extending into the first tube through a springpressed packing placed in the forward end thereof.

13. In a spray gun, the combination with a body portion having a large bore extending therethrough, of a tube adapted to extend through the rear portion of the bore and seated against a shoulder formed by a reduction in the diameter of the bore, a liquid-nozzle tube extending from the front end of the bore toward the rear thereof to be screw-threaded onto the forward end of the first-mentioned tube, said tubes being both adapted to be freely withdrawn from the body portion when they are unscrewed from each other, a needle valve for said liquidnozzle tube, an adjusting tube to regulate the extent to which the needle valve may be displaced threaded onto said needle valve, and a spring co-operating with the adjusting tube to hold the valve closed.

ROBERT D. McINTOSH. 

